All 13 men arrested during these enquiries have been released from police bail this week with no charges and no further action after independent advice from the Crown Prosecution Service (CPS) and a specialist barrister.

The men included three serving police officers who were arrested and suspended from duty in December 2014. They were questioned as part of the six initial arrests following information reported by a woman who is a member of the public.

An additional seven arrests were made in February 2015 as a result of further enquiries into related information from the same victim.

The incidents were alleged to have taken place during 2014.

A Hampshire Police statement said:

'Specialist officers from Hampshire Constabulary have met with the victim to inform her of the CPS advice and the decisions taken by Hampshire Constabulary. There are no further lines of enquiry at this time, and the allegations are not being linked to any other known cases or crimes.

'Following an extensive investigation, Hampshire Constabulary submitted a file of evidence to the Crown Prosecution Service (CPS) in February 2015.

'The CPS response acknowledged the comprehensive nature of the police investigation, and concluded that there was a lack of supporting evidence.'

Independent scrutiny has included:

- A senior detective from Thames Valley Police (TVP) was invited to carry out a voluntary independent review of Hampshire Constabulary's work on the case. This officer concluded that the investigation was "very balanced, proportionate and timely."

- The Independent Police Complaints Commission (IPCC) was voluntarily notified by Hampshire Constabulary ahead of the initial arrests. IPCC requested to be kept informed and the force has continued to liaise.

- A further layer of independence was achieved by submitting the file of evidence to CPS South East rather CPS Wessex with whom the Constabulary has a day-to-day working relationship.

"Investigating any allegation fully, irrespective of those involved, is essential to maintaining public trust and confidence in policing.

"Lines of enquiry during Operation Annaside have been conducted with meticulous care and precision due to the exceptionally sensitive nature of these allegations, and the impact on the lives, families and welfare of everyone affected.

"We have made every effort to handle this investigation with fairness, transparency and impartial scrutiny."

None of the officers will face any disciplinary proceedings as there are no grounds to suggest any misconduct. As a result, the three officers suspended from duty while on bail will return to work with Hampshire Constabulary later this year.

Supt Fry commented:

"We have full confidence in the honesty and integrity of the three officers, all of whom have been exonerated. They have been supported throughout the investigation by dedicated welfare officers and representatives from the Police Federation."

Simon Hayes, Police and Crime Commissioner for Hampshire, said:

“I recognise that the past few months must have been very stressful and difficult for the accused police officers and their families. I’m delighted that today they have been exonerated of all accusations made against them.

"The public can be reassured that a full and thorough investigation has been undertaken into an alleged sexual offences conspiracy. Given the seriousness of the allegations, it was vital that the case was investigated vigorously and I welcome the findings by the CPS today.

"I would like to commend the integrity and transparency shown by Hampshire Constabulary throughout this investigations. In particular, I would like to thank those officers who were subject to these allegations for their patience and faith in justice being done as a result of a full and thorough investigation. Today, the public across Hampshire and the Isle of Wight can be reassured by the CPS' decision that no further action should be taken against these officers.

"It is always difficult for individuals whose integrity is unfairly called into question. Whilst it is right that we encourage people to report crime, society needs to find a balance between passing early judgement before all the facts are known and being patient for proper investigation to take place.”